Generate geometry for a 3d plane and insert into ci::TriMesh

PlaneGeometry

void QuadDistrustApp::createPlane()
{
	_planeMesh = new ci::TriMesh();
	_planeMesh->clear();

	float segmentsW = 4;
	float segmentsH = 4;
	float width = 100;
	float height = width;


	std::vector< std::vector<ci::Vec3f> > grid;
	for(int i = 0; i <= segmentsW; ++i)
	{
		std::vector<ci::Vec3f> row;
		grid.push_back( row );
		for(int j = 0; j <= segmentsH; ++j)
		{
			ci::Vec3f pos = ci::Vec3f(((float)i / segmentsW - 0.5f) * width, 0, ((float)j / segmentsH - 0.5f) *  height);
			grid[i].push_back( pos );
		}
	}

	for(int i = 0; i < segmentsW; ++i) {
		for( int j = 0; j < segmentsH; ++j) {
			ci::Vec3f a = grid[i  ][j  ];
			ci::Vec3f b = grid[i+1][j  ];
			ci::Vec3f c = grid[i  ][j+1];
			ci::Vec3f d = grid[i+1][j+1];

			ci::ColorA color = ci::ColorA( ci::Rand::randFloat(), ci::Rand::randFloat(), ci::Rand::randFloat(), 0.8 );

			std::cout << a << b << c << d << std::endl;


			ci::Vec3f e0 = c - a;
			ci::Vec3f e1 = c - b;
			ci::Vec3f n = -e0.cross(e1).normalized();

			_planeMesh->appendVertex( a );
			_planeMesh->appendColorRGBA( color );
			_planeMesh->appendNormal( n );

			_planeMesh->appendVertex( b );
			_planeMesh->appendColorRGBA( color );
			_planeMesh->appendNormal( n );

			_planeMesh->appendVertex( c );
			_planeMesh->appendColorRGBA( color );
			_planeMesh->appendNormal( n );

			_planeMesh->appendVertex( d );
			_planeMesh->appendColorRGBA( color );
			_planeMesh->appendNormal( n );

			int vertA = _planeMesh->getNumVertices() - 4;
			int vertB = _planeMesh->getNumVertices() - 3;
			int vertC = _planeMesh->getNumVertices() - 2;
			int vertD = _planeMesh->getNumVertices() - 1;

			_planeMesh->appendTriangle( vertA, vertB, vertC );
			_planeMesh->appendTriangle( vertD, vertC, vertB );

		}
	}
}